OpenGL v1.1 software runtime is included as part of operating system for WinXP, Windows 2000, Windows 98, Windows 95 (OSR2) and Windows NT. So you only need to download this if you think your copy is somehow missing . The OpenGL v1.1 libraries are also available as the self-extracting archive file from the Microsoft Site via HTTP or FTP.

OpenGL v1.2, 1.3 or 1.4 are included with the drivers for your OpenGL video cards. So you only need to make sure you have the latest OpenGL driver for your video card. Each OpenGL accelerator manufacturer writes their own OpenGL drivers. So if you need a new or updated driver, go to the manufacturer's web site for your OpenGL accelerator board and download and install their latest OpenGL driver.